Check for piano actions



Feb. 18, 1936. k A. KLEIN CHECK FOR PIANO ACTIONS Filed July 12, 1935 I eii n FM? v V fldzwaw WITNESS ATTORNEY Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE Application July 12,

3 Claims.

This invention relates to the actions of upright pianos, and has especial reference to the construction and articulation of the hammer butts and their back checks, and also the means 5 for restraining the movements of the checks,

and embodies improvements over the piano action disclosed in Letters Patent of the United States No. 1,188,947, granted to me June 27, 1916.

The principal object of the invention is the provision of improvements whereby the hammer butts and their checks in an upright piano action may be economically produced and articulated, and which enables such inter-relation of the parts that repairs and replacements may be readily made should the occasion arise.

The nature of the invention and its distinguishing features and advantages will appear when the following specification is read in connection with the accompanying drawing, in which-- Figure 1 is a side elevation of a piano action selected to illustrate the invention embodied thereby;

Figure 2 is a perspective View of the back check detached;

Figure 3 is a perspective view of a detached;

Figure 4 is an enlarged section taken on the line 4, 4 of Figure l.

The piano action illustrated in Figure 1 comprises parts of conventional construction with the exception of the hammer butt and the back check connected therewith. The parts of the action operate in the conventional or usual manner.

As shown in the drawing, the action includes a hammer Ill mounted upon a butt ll pivoted as at |2 upon a stationary flange l3 so that the hammer l may strike a musical string I4. The butt II is actuated by a jack l5 to throw the hammer l0 to cause it to strike the string I4 when the key I6 is struck. In accordance with the invention, the butt II is formed to provide recesses in the opposite sides thereof respectively which will leave a reduced portion I8. Use is made of a back check l9 suitable for articulation with the butt II. To this end, the check has spaced lugs 20 on the arm 2| thereof. These lugs 20 are disposed in the recesses l'| respectively, and a pivot 22 extends transversely through the lugs 2|! and the reduced portion l8, to thus articulate the check I9 and butt II, so that the check l9 may have pivotal movement with respect to the butt II in checking the rebound of the hammer Ill carried by the butt ll.

hammer butt 1935, Serial No. 31,119

By reason of the fact that the butt H is recessed as shown and also by reason of the fact that the check I9 is provided with lugs 20 to establish the connection between these elements,

it is possible to not only produce and articu- 5 late butts and checks at low cost, but also enables repairs and replacements of parts to be conveniently made whenever necessary.

In accordance with another feature of the invention, the butt II is constructed to provide a 10 projection 23 below the reduced portion [8, so that a coil spring 24 may be employed between the butt II and its connected check l9. In other words, the coil spring 24 is arranged between the pad 25 and the projection 23 and the arm 2| of 15 the check. The arm 26 of the butt carries an adjusting screw 21 which bears on a pad 28 on the arm 2| of the check to retain it in the desired rearward adjusted position. The spring 24 has a normal tendency to urge the check [9 2o rearwardly against the screw 21 or the arm 26. The spring 24 is only strong enough to retain the check I9 seated forwardly against the screw 21 or arm 26 as the case may be, and yields readily to the rearward adjustment of the check I9 25 by the screw 21. The employment of a coil spring in the manner illustrated and described is of practical importance regarding the operation and facility in the incorporation of the spring.

With the parts shown in their normal rela- 30 tionship in Figure 1, when the key is struck, the butt II will be moved forwardly on its pivot l2 causing the hammer ID to strike the string I4. The head 29 of the jack l5 will engage the shoe 30 of the check I9, thereby holding the 35 hammer from movement in either direction when the key I6 is held depressed. When the key I6 is released, the rebound of the hammer II] will be resisted by the back check l9 bearing against the head 29.

From the foregoing, it will be obvious there has been described a simple and practical construction of the butt and back check of a piano action whereby the mentioned objects of the invention may be attained.

I claim:

1. In a piano action, a hammer butt, a back check, the opposite sides of the butt having recesses therein, said check having spaced lugs disposed in said recesses respectively, a. pivot extend- 5O ing through said lugs and butt, to thus pivotally connect the check with the butt, 9. projection on the butt, and a spring having one end engaged with said projection and the other end engaged with the check to yieldingly hold the check in operative position with respect to the butt.

2. In a piano action, a hammer butt, a back check, the butt being formed to provide a reduced portion, said check being formed to fit against said reduced portion, a. pivot extending through the check and said reduced portion, to thus pivotally connect the check with the butt, a projection on the butt below said reduced por- 10 tion, and a coil between the projection and check to yieldingiy hold the check in operative position with respect to the butt.

3. In a piano action, a. hammer butt, 9. back check having one end pivotally connected with said butt, said butt having a projection thereon, and a. coil spring between the projection and check to yieldingly hold the check in operative position with respect to the butt. 

